CCDC47 is a calcium-binding endoplasmic reticulum (ER) transmembrane protein that serves multiple essential cellular functions. It functions as a component of the multi-pass translocon (MPT) complex that mediates insertion of multi-pass membrane proteins into the lipid bilayer of membranes . Within this complex, CCDC47 specifically functions in the PAT subcomplex to occlude the lateral gate of the SEC61 complex, which is critical for proper transmembrane protein insertion .
Beyond membrane protein processing, CCDC47 plays crucial roles in:
Regulation of calcium ion homeostasis in the ER
Protein degradation via the ERAD (ER-associated degradation) pathway
Maintenance of ER organization, particularly during embryogenesis
Loss of CCDC47 function results in embryonic lethality in mice, indicating its essential role in early development . Cellular studies demonstrate that CCDC47 deficiency leads to decreased total ER Ca²⁺ storage, impaired Ca²⁺ signaling mediated by the IP₃R Ca²⁺ release channel, and reduced ER Ca²⁺ refilling via store-operated Ca²⁺ entry .
CCDC47 is an endoplasmic reticulum transmembrane protein containing coiled-coil domains, which are important structural motifs for protein-protein interactions . The protein contains calcium-binding domains with low affinity but high capacity for calcium ions . The mouse CCDC47 protein sequence begins with: MKAFYAFCVVLLVFGSVSEAKFDDFEDEEDIVEYDDNDFAEFEDT and continues through its functional domains .
Regarding cellular localization:
CCDC47 is primarily localized to the endoplasmic reticulum membrane
It is positioned to interact with the SEC61 complex at the lateral gate
As part of the PAT subcomplex, it is strategically positioned to sequester highly polar regions in transmembrane domains away from the non-polar membrane environment
This specific localization is essential for its function in protein insertion, calcium homeostasis, and ER organization during development .
The CCDC47 gene exhibits complex expression patterns. The gene contains 16 distinct gt-ag introns and its transcription produces 9 different mRNAs, consisting of 6 alternatively spliced variants and 3 unspliced forms . The gene structure includes:
3 probable alternative promoters
3 non-overlapping alternative last exons
The resulting mRNAs differ by:
Truncation of the 5' end
Truncation of the 3' end
Presence or absence of cassette exons
The CCDC47 gene is expressed at high levels in various tissues, with functional implications for calcium ion homeostasis across different cell types . This complex pattern of expression and splicing suggests tissue-specific regulation and potentially specialized functions in different cellular contexts.
For successful expression and purification of recombinant mouse CCDC47, researchers have established effective protocols that maintain protein functionality:
Expression System Selection:
The HEK-293 human embryonic kidney cell line has proven highly effective for expressing mouse CCDC47 protein fragments (Met1-Ser135) with C-terminal His tags . This mammalian expression system provides appropriate post-translational modifications and protein folding environment compared to bacterial systems.
Expression Construct Design:
DNA sequence encoding mouse Ccdc47 (NP_080285.2) from Met1-Ser135
Addition of a polyhistidine tag at the C-terminus for purification
Expression vector with appropriate promoter for high-level expression in HEK-293 cells
Purification Protocol:
Cell lysis under native conditions preserving protein conformation
Affinity chromatography using Ni-NTA resin for His-tagged protein capture
Washing steps to achieve >95% purity as determined by SDS-PAGE
Quality control to ensure endotoxin levels <1.0 EU per μg (as determined by LAL method)
Storage and Stability:
Lyophilization from sterile PBS, pH 7.4
Lyophilized proteins remain stable up to 12 months at -20°C to -80°C
Reconstituted protein solutions can be stored at 4-8°C for 2-7 days
Aliquots of reconstituted samples remain stable at <-20°C for 3 months
This methodological approach yields mouse CCDC47 protein with >95% purity and low endotoxin levels, making it suitable for functional studies, antibody production, and protein interaction analyses .
Investigating CCDC47's role in calcium homeostasis requires specialized techniques to measure ER calcium dynamics and signaling:
In Vitro Calcium Imaging Methods:
ER Ca²⁺ Storage Measurement:
IP₃R-Mediated Ca²⁺ Release Assessment:
Store-Operated Ca²⁺ Entry (SOCE) Analysis:
Genetic Manipulation Approaches:
CRISPR/Cas9-mediated CCDC47 knockout or knockdown
Rescue experiments with wild-type or mutant CCDC47 constructs
Patient-derived cells harboring CCDC47 variants for validation studies
Protein Interaction Studies:
Co-immunoprecipitation to identify CCDC47 binding partners in calcium signaling pathways
Proximity labeling techniques (BioID, APEX) to map the CCDC47 interactome
In vitro calcium binding assays to characterize direct calcium interactions
These methodological approaches have revealed that CCDC47 deficiency results in decreased total ER Ca²⁺ storage, impaired IP₃R-mediated Ca²⁺ signaling, and reduced SOCE, confirming its essential role in maintaining calcium homeostasis .
CCDC47 dysfunction has been linked to a distinct multisystem disorder with specific clinical manifestations. Researchers can model these conditions using various approaches:
Clinical Phenotype of CCDC47-Associated Disorder:
Woolly hair
Liver dysfunction
Pruritus
Dysmorphic features
Hypotonia
Global developmental delay
Neurological abnormalities (hyperreflexia, poor head control, non-verbal status)
Brain imaging abnormalities (minimal prominence of cerebral sulci, ventricular enlargement, global white matter paucity, thin corpus callosum)
Disease Modeling Approaches:
Patient-Derived Cell Models:
Animal Models:
Molecular Analysis of Patient Mutations:
Experimental Readouts for Disease Modeling:
ER calcium homeostasis disruption
Impaired protein folding and trafficking
Activation of ER stress response pathways
Developmental timing and patterning defects
Tissue-specific manifestations (neural, hepatic, dermatological)
This multifaceted approach to disease modeling provides insights into the pathophysiological mechanisms of CCDC47-associated disorders and potential therapeutic interventions.
CCDC47 plays a specialized role in the complex process of multi-pass membrane protein insertion that can be studied using advanced biochemical and cellular approaches:
CCDC47's Function in Membrane Protein Insertion:
Sequential Process with SEC61:
Role in the PAT Subcomplex:
Methodological Approaches to Study This Function:
Reconstitution Systems:
In vitro translation systems coupled with ER microsomes
Purified components reconstituted in liposomes
Cross-linking studies to capture transient interactions during insertion
Real-time Membrane Insertion Assays:
Fluorescence-based reporters to monitor membrane insertion kinetics
FRET pairs positioned at key locations to detect conformational changes
Single-molecule techniques to visualize insertion events
Structure-Function Analysis:
Mutational analysis of CCDC47 domains involved in SEC61 interaction
Cryo-EM studies of the MPT complex with trapped substrates
Computational modeling of the dynamic insertion process
Substrate Specificity Determination:
Identification of model substrates dependent on CCDC47
Characterization of transmembrane domain features requiring CCDC47
Proteomic analysis of membrane proteins affected by CCDC47 deficiency
Understanding CCDC47's precise role in membrane protein insertion has implications for numerous cellular processes dependent on proper membrane protein localization and function, including signaling, transport, and cell-cell communication .
The embryonic lethality observed in CCDC47-deficient mice indicates its essential developmental role. Researchers can employ several strategies to investigate this function:
Developmental Timing and Tissue-Specific Requirements:
Conditional and Inducible Knockout Systems:
Chimeric Analysis:
ES cell injection into wild-type blastocysts
Tracking the contribution of CCDC47-deficient cells to different tissues
Competition assays between wild-type and mutant cells
Developmental Phenotype Characterization:
Molecular Mechanisms Underlying Developmental Requirements:
Transcriptomic Analysis:
RNA-seq of early embryonic tissues in conditional knockouts
Single-cell RNA-seq to identify cell populations most affected
Integration with developmental trajectory analysis
Calcium Signaling in Development:
ER Stress and UPR in Development:
Analysis of ER stress markers during embryogenesis
Assessment of unfolded protein response (UPR) activation
Connection between ER homeostasis and developmental patterning
Mouse Embryonic Fibroblast (MEF) Studies:
These approaches would provide comprehensive insights into why CCDC47 is essential for embryonic development and how its absence leads to developmental failure, with potential implications for understanding human developmental disorders.
Ensuring the quality and functionality of recombinant mouse CCDC47 protein is critical for reliable experimental outcomes. Researchers should implement comprehensive quality control measures:
Purity Assessment:
SDS-PAGE analysis showing >95% purity
Absence of degradation products or contaminant bands
Endotoxin Testing:
Limulus Amebocyte Lysate (LAL) testing
Acceptable endotoxin levels <1.0 EU per μg of protein
Critical for cell-based assays to prevent inflammatory responses
Protein Concentration Determination:
Bradford or BCA protein assays
UV spectroscopy (A280)
Comparison against BSA standards
Functional Verification:
Calcium binding capacity assessment
Circular dichroism to confirm proper secondary structure
Thermal shift assays to evaluate protein stability
Storage Stability Testing:
Accelerated stability studies at different temperatures
Freeze-thaw cycle tolerance evaluation
Long-term stability monitoring
Batch-to-Batch Consistency:
Lot comparison by SDS-PAGE and functional assays
Certificate of analysis for each production batch
The commercial preparations of recombinant mouse CCDC47 (fragment Met1-Ser135) have been validated to meet these rigorous quality control parameters, making them suitable for a wide range of applications including structural studies, functional assays, and antibody production .
The endoplasmic reticulum-associated degradation (ERAD) pathway is critical for removing misfolded proteins, and CCDC47 plays a required role in this process. Researchers can employ several methodological approaches:
ERAD Substrate Degradation Assays:
Pulse-Chase Analysis:
Fluorescent Timer Proteins:
Expression of fluorescent ERAD substrates that change color with time
Live-cell imaging to track degradation kinetics
Flow cytometry for high-throughput analysis
ERAD Component Interactions:
Co-immunoprecipitation Studies:
Pull-down of CCDC47 to identify interacting ERAD machinery components
Reciprocal IPs with known ERAD components (HRD1, SEL1L, OS-9)
Western blot analysis of complex formation
Proximity Labeling Approaches:
BioID or TurboID fusion with CCDC47
Identification of proximal proteins in the ERAD pathway
Mass spectrometry analysis of the biotinylated proteome
Ubiquitination and Retrotranslocation:
Ubiquitination Assays:
Detection of ubiquitinated ERAD substrates
Analysis of ubiquitination patterns in CCDC47-deficient cells
In vitro ubiquitination reactions with purified components
Retrotranslocation Monitoring:
Split fluorescent protein reporters spanning the ER membrane
Protease protection assays to detect cytosolic exposure
Cell fractionation to quantify substrate localization
Proteasomal Degradation Analysis:
Proteasome Inhibition Studies:
Treatment with MG132 or bortezomib
Accumulation patterns of ERAD substrates
Comparison between wild-type and CCDC47-deficient conditions
Cellular Stress Responses:
By implementing these methodological approaches, researchers can elucidate CCDC47's specific contributions to the ERAD pathway and how its dysfunction may lead to accumulation of misfolded proteins and subsequent cellular stress.
Investigating CCDC47's developmental roles requires specialized analytical methods spanning molecular, cellular, and organismal levels:
Developmental Expression Analysis:
Spatiotemporal Expression Profiling:
In situ hybridization to localize CCDC47 mRNA in embryonic tissues
Immunohistochemistry for protein distribution during development
Reporter gene constructs (e.g., CCDC47-GFP) for live imaging
Single-Cell Approaches:
scRNA-seq to identify cell populations expressing CCDC47
Trajectory analysis to correlate expression with developmental fate decisions
Integration with developmental atlases
Embryonic Phenotyping Methods:
Advanced Imaging Techniques:
Optical projection tomography for whole-embryo analysis
Light sheet microscopy for 3D visualization of developing structures
Intravital imaging to track developmental processes in real-time
Functional Assessment:
Molecular Developmental Mechanisms:
Differential Proteomics:
TMT or iTRAQ labeling for quantitative comparison
Analysis of protein expression changes in CCDC47-deficient embryos
Focused analysis of calcium-dependent developmental pathways
Epigenetic Profiling:
ATAC-seq to assess chromatin accessibility changes
ChIP-seq for histone modifications affected by calcium signaling
Integration with transcriptomic data
Interactome Analysis in Developmental Contexts:
Stage-specific pull-downs to identify developmental binding partners
Comparison of interactions across different embryonic tissues
Validation using genetic interaction studies
Calcium Signaling in Development:
Calcium Imaging in Embryonic Tissues:
GCaMP sensors for calcium transient visualization
Correlation with morphogenetic movements
Pharmacological manipulation of calcium signaling
ER Calcium Dynamics:
These analytical methods provide a comprehensive toolkit for investigating CCDC47's essential role in embryonic development and the cellular mechanisms through which it influences developmental processes.
Research on CCDC47 has revealed its crucial roles in calcium homeostasis, protein processing, and development, suggesting several therapeutic avenues:
Targeting Calcium Signaling Pathways:
Small Molecule Modulators:
Compounds that normalize calcium flux in CCDC47-deficient cells
Selective ER calcium channel modulators
Store-operated calcium entry enhancers
Gene Therapy Approaches:
AAV-mediated delivery of functional CCDC47
CRISPR-based correction of pathogenic variants
Targeted activation of compensatory calcium regulatory mechanisms
Addressing ER Stress and Protein Misfolding:
Chemical Chaperones:
4-PBA or TUDCA to alleviate ER stress
Selective reduction of misfolded protein burden
Prevention of UPR-mediated cellular dysfunction
Proteasome and ERAD Modulators:
Developmental Disorder Interventions:
Critical Developmental Windows:
Identification of key periods for intervention
Tissue-specific approaches targeting most affected systems
Preventive strategies during embryonic development
Symptom-Specific Treatments:
Biomarker Development:
Diagnostic Markers:
Calcium flux assays in patient cells
ER stress signatures
Developmental monitoring parameters
Treatment Response Indicators:
Real-time monitoring of calcium homeostasis
Quantitative assessment of ER function
Developmental milestone achievement metrics
Research into these therapeutic avenues requires detailed understanding of CCDC47's molecular functions and the downstream consequences of its dysfunction in different cellular contexts and developmental stages.
Leveraging advanced -omics technologies can significantly enhance our understanding of CCDC47 biology:
Genomic Approaches:
Population Genomics:
Functional Genomics:
CRISPR screens for genetic interactions with CCDC47
Synthetic lethality mapping
Enhancer and suppressor identification
Transcriptomic Analyses:
RNA-Seq Applications:
Differential gene expression in CCDC47-deficient models
Alternative splicing changes
Non-coding RNA regulation
Ribosome Profiling:
Translation efficiency changes in CCDC47-deficient cells
Identification of translationally regulated targets
ER-specific translation dynamics
Proteomic Investigations:
Global Proteome Analysis:
Quantitative proteomics of CCDC47-deficient systems
Post-translational modification profiling
Protein stability and turnover assessment
Interactome Mapping:
Spatial Proteomics:
Subcellular localization changes in CCDC47-deficient cells
Proximity labeling to map microenvironments
Correlative microscopy with proteomic analysis
Integrative Multi-Omics:
Data Integration Strategies:
Combined analysis of genomic, transcriptomic, and proteomic datasets
Network analysis to identify central nodes and pathways
Machine learning approaches to predict functional relationships
Systems Biology Modeling:
Mathematical modeling of calcium homeostasis
Prediction of cellular responses to CCDC47 perturbation
Integration with developmental timing models
These large-scale approaches can reveal previously unrecognized functions of CCDC47, identify novel therapeutic targets, and place CCDC47 in a broader biological context of cellular homeostasis and development.
Recent advances in structural biology and interaction proteomics offer new opportunities to understand CCDC47 at the molecular level:
Structural Biology Approaches:
Cryo-Electron Microscopy:
High-resolution structures of CCDC47 alone or in complexes
Visualization of conformational changes upon calcium binding
Structure of CCDC47 within the PAT subcomplex of the MPT
Integrative Structural Biology:
Combination of X-ray crystallography for domain structures
NMR for dynamic regions
Cross-linking mass spectrometry for interface mapping
Molecular dynamics simulations to model conformational changes
AlphaFold2 and Structure Prediction:
In silico modeling of full-length CCDC47
Prediction of interaction interfaces
Analysis of pathogenic variant impacts on structure
Protein-Protein Interaction Technologies:
Proximity-Based Methods:
BioID, TurboID, or APEX2 fusion with CCDC47
Identification of transient and stable interactors
Organelle-specific interaction mapping
Advanced Co-IP Approaches:
Quantitative SILAC-based interaction proteomics
Cross-linking before immunoprecipitation to capture weak interactions
Native protein complex isolation followed by mass spectrometry
Protein Complementation Assays:
Split luciferase or fluorescent protein systems
Live-cell monitoring of interactions
High-throughput screening platforms
Functional Interaction Analysis:
Genetic Interaction Mapping:
CRISPR interference or activation screens
Double knockout/knockdown studies
Rescue experiments with domain-specific mutants
Single-Molecule Methods:
FRET-based assays for protein-protein interactions
Single-molecule tracking in live cells
Super-resolution microscopy to visualize CCDC47 in the ER membrane
Protein Engineering Approaches:
Domain swapping to identify functional modules
Minimal functional constructs
Synthetic binding partners for functional perturbation
These emerging techniques will provide unprecedented insights into CCDC47's structural organization, dynamic interactions, and molecular mechanisms, advancing our understanding of its role in health and disease.
Experimental Design Considerations:
Power Analysis:
Sample size determination based on expected effect sizes
Consideration of biological variability in CCDC47 expression
Stratification based on genotype or treatment groups
Randomization and Blinding:
Randomized assignment to experimental groups
Blinded analysis of phenotypic outcomes
Consideration of batch effects in protein preparation
Statistical Methods for Different Data Types:
Calcium Imaging Data:
Protein Expression Analysis:
Normalization strategies for western blots
ANOVA with post-hoc tests for multiple group comparisons
Regression analysis for dose-response relationships
Bootstrapping for robust confidence intervals
Cell-Based Functional Assays:
Survival analysis for time-to-event data
Multi-parametric analysis for high-content imaging
Principal component analysis for dimensional reduction
Machine learning classification of cellular phenotypes
Multiple Testing Correction:
False Discovery Rate Control:
Benjamini-Hochberg procedure for large-scale comparisons
q-value calculation and reporting
Conservative thresholds for exploratory analyses
Family-wise Error Rate Control:
Bonferroni or Šidák correction for confirmatory testing
Dunnett's test for comparisons against a control
Tukey's HSD for all pairwise comparisons
Reporting and Visualization:
These statistical approaches ensure robust analysis of CCDC47 functional data, facilitating reproducibility and valid interpretation of experimental findings across different research contexts.